When trading ended Tuesday night at the New York Stock Exchange, the closing bell wasn’t rung by a titan of finance or an imported celebrity. It was sounded by the CEO of an obscure defense firm with deep ties to the U.S. intelligence and special operations communities. The traders on the floor may not have recognized Mary Margaret “Peggy” Styer. But her company’s products are well known by the small group of commandos and spies who hunt down top terrorists.